Predictors of Oral Antibiotic Treatment Failure for Nonpurulent Skin and Soft Tissue Infections in the Emergency Department

Abstract

Background: Current guideline recommendations for optimal management of nonpurulent skin and soft tissue infections (SSTIs) are based on expert consensus. There is a lack of evidence to guide emergency physicians regarding selection of patients for oral versus intravenous antibiotic therapy. The primary objective was to identify predictors associated with oral antibiotic treatment failure. Methods: We performed a health records review of adults (age ≥ 18 years) with nonpurulent SSTIs treated at two tertiary care emergency departments (EDs). Oral antibiotic treatment failure was defined as any of the following after a minimum of 48 hours of oral therapy due to worsening infection: 1) hospitalization, 2) change in class of oral antibiotic, or 3) switch to intravenous therapy. Multivariable logistic regression was used to identify predictors independently associated with oral antibiotic treatment failure. Results: We identified 500 patients (mean ± SD age = 64 ± 19 years, 279 male [55.8%], and 126 [25.2%] with diabetes). Of 288 patients who had received a minimum of 48 hours of oral antibiotics, there were 85 oral antibiotic treatment failures (29.5%). Tachypnea at triage (odds ratio [OR] = 6.31, 95% confidence interval [CI] = 1.80 to 22.08), chronic ulcers (OR = 4.90, 95% CI = 1.68–14.27), history of methicillin-resistant Staphylococcus aureus (MRSA) colonization or infection (OR = 4.83, 95% CI = 1.51 to 15.44), and cellulitis in the past 12 months (OR = 2.23, 95% CI = 1.01 to 4.96) were independently associated with oral antibiotic treatment failure. Conclusion: This is the first study to evaluate predictors of oral antibiotic treatment failure for nonpurulent SSTIs treated in the ED. Tachypnea at triage, chronic ulcers, history of MRSA colonization or infection, and cellulitis within the past year were independently associated with oral antibiotic treatment failure. Emergency physicians should consider these risk factors when deciding on oral versus intravenous antimicrobial therapy for outpatient management of nonpurulent SSTIs.